I switched the time zone on my camera -12 hours and I'm trying to fix the times of the photos before the switch; however, I can't figure out where Lightroom displays AM/PM - it doesn't seem to be in the metadata panel, nor in the cell labels in grid view, nor in the "edit capture time" dialogue.
This might depend on your locality settings. In mine it shows 6:15 PM as 18:15 (exactly how I like it).
The easiest way to see this is to press
The metadata panel has to be in "default" mode (others like IPTC and EXIF will also work).
To do the adjustment on multiple images, select them all and then go into Loupe view.